1. Field of the Invention
The present invention relates to display devices including a display screen constituted by a plurality of pixels. More specifically, the present invention relates to a display device including a display screen constituted by a plurality of pixels, such as a liquid crystal display device and an organic EL (Electroluminescent) display device.
2. Description of the Related Art
Display devices which display images using a plurality of pixels have been widely used for displaying information or images. A pixel including three sub-pixels of red (R), green (G), and blue (B) has been commonly used for displaying color images, as the pixel in such display devices. Active matrix driving has been widely used as a method of driving sub-pixels in thin displays such as a liquid crystal display device which have been rapidly increasingly in demand recently. According to the active matrix driving, a plurality of gate (scanning) lines and a plurality of source (signal) lines are disposed to be perpendicular to each other in a matrix pattern. At each intersection, an active element such as a thin film transistor (TFT) is disposed and a signal applied to the active element through the gate line and the source line drives each sub-pixel, and thereby images are displayed. A configuration of the sub-pixels constituting the pixels has a great influence on whether or not high-definition and high-quality color images can be displayed. Therefore, various configurations of the sub-pixels have been investigated.
A delta array in which RGB sub-pixels are displaced by one half sub-pixel for each row; a mosaic array in which RGB sub-pixels are displaced by one sub-pixel for each row; a square array in which RGBG sub-pixels are arranged to have a square shape, and a stripe array in which sub-pixels of the same color are vertically arrayed (in one direction) have been known as an array of sub-pixels of three colors. These sub-pixel arrays are used depending on products, and particularly for products such as a high-definition display for personal computers, the stripe array is generally used.
In addition, a display device including pixels each constituted by sub-pixels of four colors including white (W) with a high luminance for improvement in luminance of display images as well as R, B, and G has been known (for example, refer to Japanese Kokai Publication No. Hei-02-118521, Japanese Kokai Publication No. 2004-78218, Japanese Kokai Publication No. Hei-11-295717, Japanese Kokai Publication No. Hei-10-10998, Japanese Kokai Publication No. Hei-05-181131, and
Japanese Kokai Publication No. Hei-04-355722). According to such sub-pixel arrays, the luminance is improved and basic performances as a display device are improved.
In the stripe array, a sub-pixel array in which sub-pixels are arrayed in order of R, G, B, W has been known as an array of four sub-pixels of R, B, G, and W (for example, refer to Japanese Kokai Publication No. Hei-11-295717). However, if the sub-pixels are arrayed in this color order in accordance with the stripe array, linear unevenness, so-called, uneven line, is generated in one direction of an image. Accordingly, such a sub-pixel array has room for improvement in order to sufficiently suppress such display defects.